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RM Italy KL 503 HD - Anybody ever use?

Wire Weasel

Senior Moment
Dec 13, 2008
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I'm considering the RM / KL 503 HD. Anyone here have any experience with these and what do you think of them? Thanks ! Screen Shot 2019-07-30 at 9.56.35 AM.png
 

The early KL503 ones were terrible with that silly unbiased driver transistor.
The HD ones might be better if all 8 are fed together but not at 300w.
200 watts PEP would probably be a cleaner output.
But the proof is in the pudding!
Who has one of these new ones?
How is it?
 
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The early KL503 ones were terrible with that silly unbiased driver transistor.
The HD ones might be better if all 8 are fed together but not at 300w.
200 watts PEP would probably be a cleaner output.
But the proof is in the pudding!
Who has one of these new ones?
How is it?
Been using for over a year now on base and mobile HD version no problems except 2 in truck lost preamp but linear still works great . puts out 250-300 with 35 watts PeP ,using 5555N11 radio with around 8 watts dead key.
 
Old Thread. Actually made a buy a couple of months ago - was still considering the 503 but the only Usual Suspects Dealer that carries them was Out of Stock. They did have some 703's so took one of those. Extremely happy with it.
 
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I have the 503 it,s my backup now worked good on SSB every one liked it . I now have the 703 same report on it to. The 503 will do 200 all day. Good amps for the money
 
I likely will not ever own one. But, some locals out where I live run them and they do well as long as they are not overdriving them. For awhile some were trying to wring every watt they could get out to of them it seems and would distort some and they would bleedover. It seems they have all settled down now, backed the input and audio down and they seem a much better amp than I initially thought!
 
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One of my buddies has one. Sounds like garbage regardless of how you drive it. SSB is even worse.
Been using for 2 years,a very good linear if used correctly, well built, used the KL503 firsts then the KL503HD drive with a 5555N11 at 35 watt PtoP power and it sounds great to every one I talked with. P-P watts 225-300 watts and Dead key around 8 watts with KL503HD using 503 use 1.5 to 2 dead key and no more than 10 watts PtoP watts
 
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